1. Field of the Invention
For an exercising apparatus using atmospheric pressure (i.e., vacuum means) as the source of resisting force, the major advantage is to reduce the total weight of the apparatus compared to an apparatus using gravity force (e.g., weight stacks) as the source of resisting force.
2. Description of the Related Art
For example, such apparatus like U.S. Pat. No. 5,336,150, "Lever Resistance Selection Mechanism for Strength Training" and U.K. Pat. GB2267224, "Exercising Device " reveal solutions for adjusting the resistance. Although U.S. Pat. No. 5,336,150 and GB2267224 disclose several types of resistance adjusting means, none of these resistance adjusting means can allow a user to adjust the level of resistance with a quick and easy process.
Therefore, a resistance device using atmospheric pressure as the source of resisting force with resistance adjusting means which can easily adjust the level of resisting force is necessary.